static Pt scalePt(Pt p, double scaleX, double scaleY default scaleX) {
  ret new Pt(iround(p.x*scaleX), iround(p.y*scaleY));
}

static Pt scalePt(double f, Pt p) {
  ret scalePt(p, f);
}

static Pt scalePt(int w, int h, double f) {
  ret scalePt(Pt(w, h), f);
}